This invention relates to a hand scanning type image input/output device whereby the picture information of a desired portion of an object, such as printed matter, is read out and the read-out information is recorded at a desired portion of a recording substrate, such as paper.
The U.S. Pat. No. 3,541,248 discloses an image input/output device including a readout unit adapted, for optically reading out the information on the surface of a manuscript, such as a book, by manual scanning, a printer for printing out optical signals from the readout unit, and a controller for controlling the readout unit and the printer. However, the device shown in the U.S. Pat. No. 3,541,248 is bulky in ovrall size and hence is not portable.
There is also proposed a manual scanning type image input/output device in, for example, the U.S. Pat. Nos. 4,716,291 and 4,611,246, according to which a main body of the device having enclosed therein readout means for reading out a desired image information from an object such as the printed matter and record means for recording the read out image information on a recording substrate, such as paper, is moved manually to scan the object thereby to enable the readout of the desired image information and the recording of the read out image to be performed on one and the same device.
This type of the image input/output device is so arranged that, after the desired image information is read out from the object, a recording head, such as a thermal head, is protruded from the main body of the device at the time that the read-out image information is recorded on the object, this recording head causing a recording tape, such as an ink tape, to abut on the recording substrate for recording the image information.
In order that the desired image information may be read with improved resolution in this type of the hand scanning image input/output device, it is necessary that the scanning be performed with the image readout surface of the object perpetually positioned within the depth of field of an optical system, such as a lens array, adapted to form the desired picture information on a line sensor constituting read-out means enclosed in the main body of the device. However, inasmuch as the hand scanner type image input device is of a small size so that it can be carried by one hand, only a small size optical system, such as a lens array, enclosed in the main body of the device, can be used, so that the optical system has only a limited field of depth.
Hence, this type of the image input device is so arranged that a readout reference surface positioned within the depth of field of the optical system is formed on the perimeter of an image information readout opening which is formed on the lower surface of the main body of the device so as to be confronted by the readout means, this readout reference surface being contacted tightly with the image information readout surface during scanning so that scanning may be performed with the image information readout surface positioned within the extremely small field of depth of the optical system.
Also, since the above described hand scanner type image input/output device can be moved freely on the object for scanning to read out the desired image information, there is provided an image information readout sensor system for sensing the amount of the read-out image information in dependence upon the distance by which the device has been moved. This sensor unit includes a roll provided on the surface of the main body of the device which is in contact with the object and a rotary encoder driven into rotaion on the basis of the rotation of the roll for detecting the readout amount of the image information.
However, in the above described image input device, when the roll is provided on the surface of the main body of the device in contact with the object, the readout reference surface cannot be contacted tightly and accurately with the image information readout surface, so that the image information readout surface can no longer be positioned within the field of depth of the optical system and hence the readout operation of the image information with high resolution cannot be realized.
Also, should the roll remain stationary within the main body of the device, it may float due to, for example, distortion of the image information readuot surface, so that the rotary encoder cannot be revolved in synchronism with the movement of the device and hence the read-out amount of the image information cannot be detected accurately.